1 research outputs found
Electrochemical DNA Biosensor Based on a Tetrahedral Nanostructure Probe for the Detection of Avian Influenza A (H7N9) Virus
A DNA tetrahedral nanostructure-based
electrochemical biosensor was developed to detect avian influenza
A (H7N9) virus through recognizing a fragment of the hemagglutinin
gene sequence. The DNA tetrahedral probe was immobilized onto a gold
electrode surface based on self-assembly between three thiolated nucleotide
sequences and a longer nucleotide sequence containing complementary
DNA to hybridize with the target single-stranded (ss)ÂDNA. The captured
target sequence was hybridized with a biotinylated-ssDNA oligonucleotide
as a detection probe, and then avidin-horseradish peroxidase was introduced
to produce an amperometric signal through the interaction with 3,3′,5,5′-tetramethylbenzidine
substrate. The target ssDNA was obtained by asymmetric polymerase
chain reaction (PCR) of the cDNA template, reversely transcribed from
the viral lysate of influenza A (H7N9) virus in throat swabs. The
results showed that this electrochemical biosensor could specifically
recognize the target DNA fragment of influenza A (H7N9) virus from
other types of influenza viruses, such as influenza A (H1N1) and (H3N2)
viruses, and even from single-base mismatches of oligonucleotides.
Its detection limit could reach a magnitude of 100 fM for target nucleotide
sequences. Moreover, the cycle number of the asymmetric PCR could
be reduced below three with the electrochemical biosensor still distinguishing
the target sequence from the negative control. To the best of our
knowledge, this is the first report of the detection of target DNA
from clinical samples using a tetrahedral DNA probe functionalized
electrochemical biosensor. It displays that the DNA tetrahedra has
a great potential application as a probe of the electrochemical biosensor
to detect avian influenza A (H7N9) virus and other pathogens at the
gene level, which will potentially aid the prevention and control
of the disease caused by such pathogens